Recently, as existing energy sources such as petroleum and coal are expected to be depleted, interests in alternative energy sources for replacing the existing energy sources are increasing. Among the alternative energy sources, solar cells for generating electric energy from solar energy have been particularly spotlighted.
A solar cell generally includes semiconductor parts, which respectively have different conductivity types, for example, a p-type and an n-type and thus form a p-n junction, and electrodes respectively connected to the semiconductor parts of the different conductivity types.
When light is incident on the solar cell, a plurality of electron-hole pairs are produced in the semiconductor parts and are separated into electrons and holes by the incident light. The electrons move to the n-type semiconductor part, and the holes move to the p-type semiconductor part. Then, the electrons and the holes are collected by the different electrodes respectively connected to the n-type semiconductor part and the p-type semiconductor part. The electrodes are connected to each other using electric wires to thereby obtain electric power.
A plurality of solar cells having the above-described configuration may be connected to one another through intercell connectors to form a module.
In a related art solar cell in which amorphous silicon or polycrystalline silicon was deposited on one surface of a semiconductor substrate, it took a relatively long time to deposit silicon on one surface of the semiconductor substrate, which was a hindrance to an increase in a production amount of the solar cell.
For example, a technology in which polycrystalline silicon was deposited on a surface of a semiconductor substrate to form a conductive region was disclosed in U.S. Pat. Publication Nos. 5,786,027 and 8,242,354.
However, such a related art deposited silicon on an entire surface of each semiconductor substrate in a process for depositing silicon on the semiconductor substrate. In the related art, because the process for depositing silicon on the semiconductor substrate was separately performed on each of the semiconductor substrates, there was a limit to a reduction in a process time of the solar cell.